Re: [Qemu-devel] [PATCH 05/10] block: remove BlockDriver.bdrv_write_compressed

[Pavel Butsykin <pbutsykin@virtuozzo.com>]

On 16.05.2016 19:57, Eric Blake wrote:
> On 05/14/2016 06:45 AM, Denis V. Lunev wrote:
>> From: Pavel Butsykin <pbutsykin@virtuozzo.com>
>>
>> There are no block drivers left that implement the old
>> .bdrv_write_compressed interface, so it can be removed now.
>>
>> Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
>> Signed-off-by: Denis V. Lunev <den@openvz.org>
>> CC: Jeff Cody <jcody@redhat.com>
>> CC: Markus Armbruster <armbru@redhat.com>
>> CC: Eric Blake <eblake@redhat.com>
>> CC: John Snow <jsnow@redhat.com>
>> CC: Stefan Hajnoczi <stefanha@redhat.com>
>> CC: Kevin Wolf <kwolf@redhat.com>
>> ---
>
>> +++ b/block/io.c
>> @@ -1876,7 +1876,6 @@ static void bdrv_write_compressed_co_entry(void *opaque)
>>   int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
>>                             const uint8_t *buf, int nb_sectors)
>>   {
>> -    BlockDriver *drv = bs->drv;
>>       BdrvWriteCompressedCo data = {
>>           .bs         = bs,
>>           .sector_num = sector_num,
>> @@ -1885,19 +1884,6 @@ int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
>>           .ret        = -EINPROGRESS,
>>       };
>>
>> -    if (!drv) {
>> -        return -ENOMEDIUM;
>> -    }
>
> Why are you deleting this check?
>

Because this check is duplicated in bdrv_co_write_compressed(), but
in this place it was necessary for drv->bdrv_write_compressed.